1.Field of the Invention
The present invention relates to a composition and use of the composition, and, in particular, relates to a halogen-free flame-retardant resin composition including recycled polycarbonate and recycled polyethylene terephthalate and a copier/printer exterior part using the resin composition.
2.Description of the Related Art
With continuous and rapid development of the plastic industry, plastic products have been widely used. At the same time, however, plastic waste has increased, and a huge amount of energy sources has been wasted. Accordingly, collection and reuse of plastic waste has attracted more attention than before.
Plastic materials are chemicals derived from petroleum. It is well known that petroleum is a lifeline for the industries of the present age and a natural source which cannot be reproduced. According to statics of a related organization, plastic waste generated by one medium-sized city per year can cover plastic materials demanded by 20 small and medium-sized plastics companies per year. Hence, reuse of plastics can be regarded as reuse of petroleum. By melting and granulating plastic waste, supply-demand imbalance in plastic materials can be reduced, and a national budget for petroleum import can be drastically cut.
Polycarbonate (PC) has excellent impact resistance, heat resistance, dimensional stability, electric insulation and the like, is nontoxic, and has low water absorbency. Accordingly, PC can be used in a wide range of temperatures. In addition, because PC has high light transmittance of 90%, it is named “transparent metal”, and used instead of copper or other colored metals in various fields, such as the electrical and electronic industry, the automobile industry, the mechanical industry, the optical industry, and the pharmaceutical industry. In recent years, consumption of PC has rapidly and continuously increased, and unavoidably, a large amount of PC waste has been generated. PC waste is an important recycled source, and it is necessary to properly process PC waste so as to reduce influence of PC waste on environments. Collection and reuse of PC waste contribute to economic and social benefits significantly. Examples of PC waste to be collected include PC used in buckets, dies, and optical disks.
According to data by PCi (PET Packaging, Resin & Recycling Ltd), in 2008, production capacity of polyethylene terephthalate (PET) in the world reached 67 million tons, and output thereof was 61 million tons. Meanwhile, several million tons of PET waste, which is generated by consumption of a large amount of PET, is generated every years. If PET waste is not sufficiently used, a large amount of resources is wasted. Nowadays, recycled PET is mainly used in fibers, sheets, and bottles for containing nonfood, and used in some plastic bottles, monofilaments, and the like. However, the application range of recycled PET is relatively narrow in the engineering plastic field. In particular, application thereof in the plastic alloy field is hardly reported.
In U.S. Pat. No. 7,462,649,there is disclosed decomposing a PET bottle or the like, and performing repolymerization by ester interchange, so as to realize production of a bottle from a bottle.
Furthermore, in Chinese Patent Application Laid Open Publication No. 101338070, there is disclosed preparing a composition containing flame-retardant PC and a polyester resin, which are denaturalized by an epoxy group-containing rubber modified aromatic vinyl copolymer resin, but not disclosed using a recycled material.
Engineering PET has low viscosity/toughness in general, and recycled PET has lower viscosity/toughness. Hence, unless the viscosity/toughness is increased, the application range of recycled PET is not widened. Furthermore, influence of low molecular weights and wide distribution of molecular weights of recycled PET on performance thereof is more than that of recycled PC on performance thereof, and hence a composition including recycled PET and a product using the composition are unstable in performance, and difficult to obtain stable mechanical performance. Consequently, the application range of recycled PET is somewhat limited.
Therefore, development of a halogen-free flame-retardant resin composition including recycled PET and recycled PC and a product using the resin composition has an important meaning in terms of environmental protection and practical application.